Valve cover... if it's got the steel backed neoprene... reuse it or buy one and TORQUE TO SPEC.
The pan gasket, IIRC, is a rubberized gasket. If I was determined to make one I'd probably use a skin of ultra blue over it on both sides to cover my errors. For both the exhaust and oil pump I'd just buy the right gaskets and use them dry without sealant. None of those gaskets are so expensive that it's worth the time to not buy them.... except the cover gasket... and that's reusable.